Method of treating photoresists

Abstract

Ultraviolet radiation process applies to manufacture to semiconductor devices in order to enhance the thermal stability of the developed positive photoresist film on semiconductor's wafers. A method, in ultraviolet radiation process, and an apparatus enabling the high-speed and effective treatmnent of the positive photoresist employing ultraviolet irradiation by preventing the deformation of the positive photoresist which is caused by the light radiated form the microwave-excited electrodeless discharge lamp. These method and apparatus employ ultraviolet irradiation, in which ultraviolet rays are applied to the developed positive photoresist image placed under lower or pressure than 1 atmospheric pressure, using a means to intercept or reduce selectively all or part of the wavelengths in the spectral response region of the positive photoresist out of radiant lights obtained from the microwave-excited electrodeless discharge lamp.

What is claimed: 
     
       1. A method of enhancing thermal stability of a developed positive photoresist image on a semiconductor wafer comprising the steps of: energizing a microwave-excited electrodeless discharge lamp to provide a range of radiant energy including wavelengths of 300 nm to 500 nm,   selectively filtering wavelengths in the spectral response region of said photoresist image from said radiant energy,   placing the developed positive photoresist image in a chamber having a gas at a pressure lower than 1×10 -1  torr atmospheric pressure, and exposing said photoresist image to the wavelengths remaining in said radiant energy after said filtering step.   
     
     
       2. The method defined by claim 1 wherein said gas is air and said microwave-excited electrodeless discharge lamp is a mercury vapor lamp.